Bug Description

Binary package hint: xserver-xorg-input-synaptics

The original description of this bug isn't valid now. Although the bug initially was filed for having true multitouch capability but as the majority of subscribers as well as the bug reporter wants to accept and use the emulation workaround, this bug now deals with emulation workaround. This is done just to clean up all the bugs that are filed for multitouch. Now all bugs that deal with two finger scroll on older touchpads(or for any other reason those who want their bug reports should be happy with emulation workaround) should be marked as duplicate of this bug.

If anybody wants to track the status of the bug that deals with true multitouch(hardware based, not using emulation) please subscribe here also bug #308191. All the bug reports that want their bug reports were actually filed for true multitouch should be marked duplicate of that bug.

In any case all bugs related to multitouch should be marked duplicate of either this bug or the later bug(only do if the hardware is synaptics).

First of all thanks for reporting the bug report and help us to make ubuntu better ... cheers

@dbosen @Schmankerl

Your two finger scroll seemed to work with the workaround but can you see the button 'Two finger Scroll' in your System>Prefrences>Mouse under the Touchpad tab. Is the button active or deactive both before and after the workaround..

This will help us to remove the bug form the next package releases ...

Please confirm the change in bug discription ... This is a known bug and is being worked upon by the developers already. In this case you could probably help us in a way if you could upload the files I requested from a laptop having a synaptics touchpad too and whose two finger scroll works ...

If the above command produces an error, you don't have a compatible touchpad. If it doesn't produce an error, but two-finger scroll doesn't work either, try adjusting the value of EmulateTwoFingerMinW and EmulateTwoFingerMinZ in the above command and executing it again. A smaller value in EmulateTwoFingerMinW will accept a narrower touch to activate scrolling.

3. To make changes permanent, follow the instructions in the attached file.

when I use this and I try to tap right click is invoked even with just one finger or with two fingers. Jeff this is just an emulation and it will work with any touchpad even with the oldest one, provided that should be recognised as a touchpad and synaptics module is loaded. But surely this has a flaw that i is just a emulation and uses that fact that when a person uses two fingers on the touchpad he doesn't use it at the same time these always a time lag between them. This is never perfect too. Inspite this trick cannot be used to emulate pinch zoom etc ...

These patches are good if it provide a relief to the bug reporter and the affects people but are not the correct FIX. When this touchpad can support multitouch emulation should not be recomended. The bug is in the kernel instead which recognises that the touchpad doesn't support multitouch instead. Still I will talk to developers that where the bug should be categorised instead ...

1. If scroll is invoked with one finger, increase the value of EmulateTwoFingerMinW. Yours is 3, which is very small. A value of 5 works well for me, but your number may vary, depending on your touchpad and your fingers.

2. It's not a fix, it's a workaround. A fix would involve a patch to gnome-mouse-properties.

3. This bug is not about multitouch, but about two-finger scroll. Since my workaround allows two-finger scroll, I think it's a valid workaround. There is another bug for multitouch. If a person wants two-finger scroll, what difference does it make if he gets it through multitouch emulation or through real multitouch? I don't understand your complaint.

4. Pinch/zoom via multitouch are features that depend on application support as well, and to the best of my knowledge no applications support for Ubuntu support these gestures, so this is more than a driver issue.

Jeff: Although your suggestions could indeed provide a reasonably working workaround for some users, it is not the preferred way for fixing this problem.

Although it can indeed by useful for the reporter to work around the problem with the configuration files, we shouldn't consider providing only one feature of multi-touch support via emulation using this configuration. There are two reasons for this:
1) We would have to recognise multi-touch somehow anyway, otherwise we can't enable emulation when it is expected.
2) Using software emulation of a feature that should be supported by the (kernel) driver is not how we want things to work in Ubuntu. This issue should be solved properly, and that means it is indeed a duplicate of bug #308191.

I agree that a more thorough solution is better, and it's not for me to say how Ubuntu should allocate human resources. But for users, like me, who just want to be able to scroll with two fingers, there is a solution today that works, whereas a comprehensive multitouch solution, touching on kernel, drivers, desktop environment, and applications, is months or years away.

Jeff: Bug reports are not just like forums where users diagnose just their own machines on expert advice but much more. These are used by bug fixers to fully eliminate the problem in future versions of Ubuntu. I truly agree to your point, you have provided your workaround and that could be a big relief to people here but it should be marked as a duplicate for two reasons :

1. Workarounds are not solutions, only temporary relief to user who want to use multitouch on their laptops. But to make Ubuntu better the bug has to be dealt by expert bug fixers. Such duplicate bugs helps them to look at various different hardware configuration where the problem exist.

2. As we group all the possible bug reports together, the bug reporters will themselves look at similar other bug reports and may find a useful solution themselves. This happens many times. This way your solution may also help may others and not just here.

We should not mark this bug as duplicate, only if the solution of this bug is in a different way. So separate developer will take on this which is not desirable.

Further Jeff, we wish to provide user all the features that their hardware provide in a best possible way. So if someone is not able to control screen brightness, and files a bug, changing colors from the Nvidia panel may be a temporary relief(which may provide the same effect) but still not solution as this alternative solution consumes more battery power. When hardware vendors introduce features in hardware that has a emulation possible through software, we should trust them, that they did it for the good and surely for the better possible outcome.

Everyone wants Ubuntu to be as good as it can be. Idealistic notions aside, the fact is that there is a limited amount of manpower to attend to these bugs. So, in the interest of expediting a fix that will be adequate to the largest number of users, I'll compare these bugs:

bug 554980 can be fixed with a simple patch to gnome-mouse-properties. In fact, it was working in Jaunty, and this represents a regression. Multitouch emulation is in the system, it works, and it simply needs a GUI to activate it. This could even be done in lucid-updates.

bug 308191 touches a lot of packages and much of the required code isn't deployed. There is no way this can be done in Lucid and probably not even in Maverick. Even with a far-off, allegedly superior solution that would resolve bug 308191, the user experience would be exactly the same as if we fixed bug 554980. Genuine multitouch and multitouch emulation, at this point, are indistinguishable to an end user. And while "expert bug fixers" are spending time on a more difficult solution, they are neglecting other, far more serious, bugs.

So, we have to choose: if we value a user experience, which enables two-fingered scrolling in the near future, let's fix this bug. If we want to spend years in development creating the ultimate solution, while users get a sub-par operating system, then let's ignore this bug and focus on 308191.

In any case, this is not at all my decision to make. I'm just a user to would like to have a solution that works as soon as possible. If the Ubuntu community decides otherwise, so be it.

Jeff: Everyone who uses Ubuntu is a part of the Ubuntu community and has an equal right to decide things and we aims to provide our users the best possible experience. Regarding the end user experience of the genuine approach and emulation approach, its not true that both are same, otherwise why would have the hardware approach created .

I don't know how can one make a patch(a deb file) which can set variable properties synclient TapButton2=3 HorizTwoFingerScroll=1 VertTwoFingerScroll=1 EmulateTwoFingerMinZ=29 EmulateTwoFingerMinW=5 JumpyCursorThreshold=200 which are different for different touchpads. Jeff another point is that emulation work good for some touchpads while very bad for others.

It is a good idea to make a relief patch until the bug #308191 is resolved but that is not possible as fas my knowledge is concerned. If you or someone can make one, we will be really happy to distribute such a patch which will emulate multitouch for users but if it works on some and not on others and the some users have a bad experience with it, that not good idea, you know. Even if a less general patch that could only correct synaptics touchpad is also accepted, that way two or more patches can be released. But in this case I don't even that is possible, we only have to make a thousand patches for this. Normally in such situations where variable properties has to be set users or developers provide workarounds like you did so someone following that can correct it for themselves. If we get a all 'applicable patch' that could be distributed without thought.

However the duplicate status of this bug will still remain even if the patch is released as the true solution is by bug #308191 even if this happens for many years to come.

I consider the majority's demand and I think the emulated approach of the synaptics touchpad seems to be good enough. I see if we could patch the workaround of Joe, we are more than happy, not to suffer the user experience by providing a patch, since this is Ubuntu all about. However the final decision lies with the upstream developers.

Ubuntu is neither controlled by majority, nor by community however by logic. While discussing this bug in the community, we realise at some point that this bug could be treated as a papercut. At the end I think your effort in this regard did worked and I really enjoyed discussing the treatment of this bug with you. Now if patch is possible, we could probably distribute it.

Cheers

summary:

- two finger scroll not working on SynPS/2 Synaptics TouchPad.+ Two finger scroll not working on SynPS/2 Synaptics TouchPad.

only problem i have w/ post 23 is that I can no longer click & drag, as the HP envy 15 i'm using has a "clickpad" style touchpad w/ no distinct buttons -- so the drag gets treated as a 2nd finger -> scroll... not sure if there are some config tweaks that could prevent that?

You will happy to know that an experimental version of the 'multitouch protocol' based dkms package is released here in bug #308191 which is providing true multitouch support for people who have touchpads with true multitouch capabilities(like in some latest synaptics touchpad). So if that works for you unsubscribe here and continue there instead..